The present disclosure broadly relates to the art of printing systems and, more particularly, to a printing system capable of identifying residual sheets of media within a transport pathway while in a non-productive condition and in preparation for restoring the printing system to a productive condition as well as a method of operation.
The terms “print”, “printing” and “marking” as used herein are to be broadly interpreted to encompass any action or process involving the production or output of sheet media having text, images, graphics and/or other indicia formed thereon by any process, such as inkjet or electrophotographic processes, for example.
The terms “printer” and “printing system” as used here are to be broadly interpreted to encompass any device, apparatus or system that is capable of performing a “printing” action. Examples of such equipment and/or systems include, without limitation, desktop printers, network printers, stand-alone copiers, multi-function printer/copier/facsimile devices, high-speed printing/publishing systems and digital printing presses.
Additionally, such exemplary embodiments of equipment, systems and/or processes can utilize sheet media of any suitable type, kind, material, quality and/or thickness (e.g., recycled paper, plain paper, bond paper, coated paper, card stock, transparencies and/or other media). Furthermore, such exemplary equipment, systems and/or processes can output indicia on such sheet media using any printing or marking substance, such as liquid ink, solid ink, toner and/or colorant, for example, in monochrome (e.g., black) or one or more colors, or any combination thereof.
Further still, the term “productive condition” as used herein is to be broadly interpreted to encompass conditions in which a printing system is presently capable of generating printed output or performing any output generating or related action. For example, a printing system in “productive condition” will normally be powered on, include a usable quantity of consumables (e.g., at least some toner, ink or other marking substance, at least some sheet media, at least some fuser oil), and have an operating system in a ready state (i.e., an active or a sleeping state) that is capable of initiating operation within a short duration, such as less than 10 seconds, for example. The term “non-productive condition” as used herein is to be broadly interpreted to encompass conditions in which a printing system is presently capable of some operation and movement but is presently incapable of generating printed output or performing any output-generating actions. For example, a printing system in a “non-productive condition” will normally be powered on, include a usable quantity of consumables, include an operating system that is active and functional but which is incapable of generating printed output due to an unresolved issue with a component or system. The terms “cycle-up,” “cycling-up,” “warm-up” and “warming-up” as used herein are to be broadly interpreted to encompass any action or process performed internally by a printing system to return the printing system to a productive condition, such as from an OFF condition (e.g., a no electrical power condition) or a non-productive condition. For example, upon being turned on by a user, a printing system may go through a series of actions, such as energizing components, heating printing elements, checking consumable levels and/or performing various self tests, for example, upon the successful completion of which actions the printing system may be in a productive condition.
Additionally, the subject matter of the present disclosure is particularly well suited for use on and in association with larger printing systems, such as high-speed printing/publishing systems and digital production presses, for example, and will be discussed herein with particular reference thereto. However, the subject matter of the present disclosure is capable of broad use in a wide variety of applications and environments. As such, it is to be distinctly understood that the showings and discussion herein are merely exemplary and are not intended to be limiting.
During normal usage, it is common for printing systems to discontinue operation due to the occurrence of certain events and/or conditions, such as upon exhausting a supply of sheet media, exhausting a supply of fuser oil or upon the initiation of a print quality adjustment, for example. In such situations, printing systems are normally capable of suspending operation in such a manner that the sheets of media actively within the printing system, namely, along the media pathway thereof, are delivered to a suitable sheet media outlet to thereby clear the media pathway. So, upon resolution of the event or condition that caused the discontinuation of operations, the printing system will typically be capable of restoring operation without requesting the performance of any other corrective actions or measures by a user or operator.
In other situations, however, unexpected interruptions in the operation of printing systems can occur. Such unexpected interruptions generally do not permit the printing system to suspend operation in a controlled manner. As a result, the printing system will normally lose track of at least some of the sheets of media within the printing system. One example of such an unexpected interruption in operation is commonly associated with the actual transportation or movement of sheet media along the media pathway. More specifically, one or more sheets of media can become disassociated with the media pathway and impede the movement of other sheets of media therethrough. For example, a portion of a sheet of media may become lodged within the structure of the printing system while the sheet of media is traveling along the media pathway. This can result in the sheet of media becoming drawn outside of the pathway, and often results in the sheet becoming wrinkled, torn or otherwise damaged. However, it will be appreciated that the foregoing is merely one example of a source for an unexpected interruption in operation of a printing system. Accordingly, it will be recognized that such unexpected interruptions can also occur for other reasons, such as due to external power failures, for example.
After an unexpected interruption in operation occurs, regardless of the cause thereof, it is common for printing systems to enter a non-productive condition in which some or all of the sheets of media within the transport pathway are to be removed by a user or operator in preparation (i.e., cycling-up) for the resumption of operation of the printing system. For example, in some printing systems the sheets may be removed from only a small section of the media pathway. Whereas, in other printing systems the entire media pathway of the printing system may be cleared. In situations in which the unexpected interruption was caused by an anomaly in the transport of a sheet of media, any wrinkled, torn or otherwise damaged sheets are also removed.
Many known printing systems include one or more sheet media sensors strategically disposed along the media pathways of the printing system. These sensors are generally used for various operation and performance-related functions of the printing system. Additionally, such sheet media sensors are commonly used to aid in locating sheets of media within the printing system, such as after the occurrence of an unexpected interruption. For example, a printing system will often include a graphical user interface that is capable of displaying a representation of the printing system and/or media pathway. The location of any sheets of media within the media pathway that are observed by the sheet media sensors can be indicated on the graphical interface to aid the user or operator in locating those sheets. Normally, the user or operator will then access the areas of the media path indicated on the graphical interface through suitable access components and clear any sheets that are visible within that area.
Once all visible sheets of media have been removed by the user or operator, the one or more access components of the printing system that have been opened to access the transport pathway are closed by the user or operator. Normally, printing systems include communication devices that are capable of recognizing when an access panel or other component of a printing system is opened or in a condition that is other than a fully closed condition. With all of the access components properly closed, a conventional printing system will then begin to fully cycle up in preparation for normal printing operations.
One difficulty with the foregoing known arrangement and process, is that it is possible for one or more sheets of media remain within the transport pathway even though it is believe to have been fully and properly cleared of sheet media by the user or operator. That is, one or more sheets of media may have become “lost” within the media transport pathway due to the unexpected interruption in operation. For example, the sheet of media may not have been visible to the user or operator during the clearing operation due to the vantage point from which the media pathway was being observed. Alternately, the one or more “lost” sheets of media simply may not have been identified by the one or more sheet media sensors of the printing system.
With reference to this latter possibility, it is well understood that sheet media sensors are strategically positioned within printing systems along the media transport pathways thereof. Due to the length of the media pathways of many printing systems, however, it is possible for some adjacent media sensors to be spaced from one another a distance that is greater than the size of a sheet of media. While such spacing arrangements are typically inconsequential for the performance and operation of the printing system, it is possible for a sheet of media to become “lost” within these areas during an unexpected interruption in operation.
As mentioned above, one disadvantage of known arrangement and process, is that it is possible for one or more residual sheets of media remain within the transport pathway even though the pathway is believe to have been fully and properly cleared. This situation is undesirable because printing systems can often take a significant duration to fully warm-up in preparation for a return to operation. One function that is performed while a printing system is cycling-up (i.e., preparing to return to a productive condition) commonly involves rotating the various drive rollers, nips and other sheet media movers of the printing system. In doing so, however, any residual sheets of media that have not been removed from the media pathway will normally be advanced over a sheet media sensor, which typically causes the printing system to discontinue any ongoing operations (i.e., warm-up activities) and await the clearing of the sheets of media by the user or operator.
To clear the newly-identified (i.e., residual) sheets of media, a user or operator will again displace one or more access panels or other components to access the media pathway and remove the one or more newly-identified sheets of media. The user or operator will then, again, displace the one or more access panels or other components to close or otherwise re-cover the media pathway. With all of the access panels and/or other components properly in place, the printing system can one again prepare to return to operation by initiating the cycle-up or warm-up procedure. In some cases, the foregoing process may be repeated several times before all of the sheets of media have been cleared from the transport pathway.
Though the overall delay may be relatively short for smaller printing systems, it is, nonetheless, desirable to avoid the foregoing interruptions in the warm-up process and the disadvantages attendant thereto. Additionally, the foregoing difficulties can be particularly problematic for very large printing systems, such as high speed/high volume printing systems and digital printing presses, for example, in which the paper paths may be substantially longer, sheet media sensors are often spaced greater distances apart, and cycle up times for the printing system significantly increased.